Clinical Research Directory

Inclusion Criteria: * Adult patients over 19 years old, undergoing non-emergent cardiac surgery with cardiopulmonary bypass at the Saint John Regional Hospital (SJRH). Exclusion Criteria: * Emergent surgery. * Severe renal or hepatic impairment (creatinine clearance (CrCl) \<30 mL/min, Chronic Kidney Disease (CKD) stage ≥4, cirrhosis, Alanine Transaminase (ALT) ≥ 3 × upper limit of normal (ULN)). * Sleep apnea. * Restless leg syndrome (RLS). * Insomnia with chronic use of pharmacological sleep aids prior to admission (trazodone, benzodiazepines, zopiclone, mirtazapine, quetiapine, tricyclic antidepressants \[nortriptyline, amitriptyline, doxepin\]). * Prior use of a monoamine oxidase inhibitor in the past 14 days. * Corrected QT Interval (QTc) \> 500ms / history of prolonged QTc, Torsade de points or ventricular tachycardia. * History of dementia, alcohol, or opioid use disorder. * Documented or previous intolerance to melatonin, trazodone, or quetiapine. Unable to provide informed consent. Run-in Period Exclusions: After enrolment and before randomization, participants will be monitored for specific postoperative criteria. Those meeting any of the following criteria will be withdrawn prior to randomization. * Radial artery harvest required (unable to place Fitbit device on the wrist contralateral to the arterial monitoring line). * Prolonged intubation or sedation (\> 48 hours) post-surgery. * Major intra- or early postoperative complications (stroke, transient ischemic attach (TIA), major bleeding, need for mechanical/circulatory support, reoperation, open chest, pulmonary embolism, acute renal failure requiring dialysis or other major surgical complications that would inhibit ability to participate).